Currently, rolls of photosensitive web are generally shipped from the manufacturer to the customer in containers, such as corrugated boxes. The rolls are first wrapped in a light tight bag prior to being placed in the shipping box. Experience has indicated that a significant percentage of these rolls are damaged during transportation due to mishandling. A principal cause of such damage is that the bag and corrugated box offer little impact resistance when the package is dropped or mishandled. When the package is dropped the inertial weight of the roll hitting a stationary object is enough to crush the center core of the roll. This center core is typically made from a rolled paper board and must remain circular so that the roll can be mounted to the mating spindle on a photo finisher's printing machine.
Crushed cores are the most common form of damage that occurs when the package impacts an obstruction along one of the four side flat faces of the box. Another form of damage includes denting of the outer laps of the paper roll. This is caused when the package hits an obstruction from an oblique angle or along one of the edges of the box. During this type of impact there is a very focused amount of energy imparted on the roll at its edges which causes denting and sometimes bruising of the roll of web.
Another failure mode of current packages of rolls of photosensitive web is roll telescoping. This is caused when the corrugated box distorts to a point where the end face of the roll is no longer fully supported. The roll responds by allowing the individual laps to move axially relative to one another forming what looks like a telescope.
Conventional end plates that support and locate paper rolls within a card board box are available from various manufacturers but have significant draw backs and can not be used to solve the above problems. First, they tend to be standardized to sizes which are significantly larger or smaller than photographic paper rolls. Second, they are typically non-continuous on the surface which supports the roll. Thus, during impact the end plate would leave impressions on the sensitive photographic paper. Third, conventional endplates are generally not designed for rolls as heavy as photographic paper. Consequently, to scale up one of these designs to handle the requirements of photographic paper the end plate wall thicknesses would be very thick, causing high production costs due to excess material usage and increased processing cycle time. Also, these thick sections at the central hub would tend to impart large reaction forces to the core of the roll such that ovalization of the core would occur. Yet another draw back to scaling up conventional end plate designs is that the large wall thicknesses would be prone to cracking from the excessive stresses built up during impact. The upscaled end plate would behave more like a ram than a bumper in that energy would be reflected instead of absorbed. Yet another disadvantage to conventional end plates is that the end plates are typically rectangular in shape. Tests have shown that a round roll only needs a round plate. Additional material only provides greater leverage of the destructive forces. Also, rectangular plates pose difficulties in automatic packaging.
One prior art attempt to solve these problems includes U.S. Pat. No. 5,232,092 which teaches a shock shield which permits rotation of tape reel within a shipping or storage case and which also absorbs shocks. The shock shield is formed by an annular body having a central axial hole which mounts within a case. Shock absorption is accomplished by compressible V-shaped annular bearing rings formed on the shield body. While the shock shield therein disclosed may have sufficed for its intended purpose, it does not fulfill the present need set forth hereinabove.
U.S. Pat. No. 3,260,362 discloses a roll suspension piece for shipping rolls of film. The suspension piece comprises a plastic molded flat backing with an integral hub, with the outer shape being octagonal in shape. Ribs below the flat backing are made integral with the central hub, forming a very rigid strong central support.
U.S. Pat. No. 4,570,794 discloses a bulk package of film rolls, each film roll physically separated from confronting surfaces of the package. This is accomplished with the use of separating plates and a removable mandrel supported by end caps.
U.S. Pat. No. 4,826,008 discloses a package for light sensitive materials consisting of a tubular section and mating removable end closures. The removable end closures have light tight channels which can be made with a bayonet or screwable feature for joining to the tube section.
U.S. Pat. No. 5,167,322 discloses a wrapped package of wound material. The wrapping is affixed to the wound web by means of an end header and support disk. The support disk traps the wrapping on the end and provides support to the roll edges when placed on its side such that roll telescoping does not occur.
Accordingly, there persists a need for an economical, light weight, easy to manufacture and use, support plate that can attenuate and thus absorb impact energy before it reaches and damages the product supported thereon, such as a roll of photosensitive web.